The filter to apply on the results of DescribeCustomerGateways.
Remarks
Filters can be:
a. state - The state of the Customer Gateway. (pending,
available, deleting, deleted).
b. type - The type of Customer Gateway. Currently the only
supported type is ipsec.1.
c. ipAddress - The IP address of the customer gateway's
Internet-routable external interface (e.g., 12.1.2.3).